Railroad track rails and cross ties are conventionally supported on beds of stone ballast. The stone ballast provides a firm foundation for the cross ties and rails, and the spaces between the stone ballast allows for proper drainage of rain water away from the railroad track. Over time, the spaces between the individual stones of the stone ballast can become fouled with mud and debris. The fouling of the ballast interferes with proper drainage, thereby contributing to premature deterioration of the wooden cross ties, and detracting from the firmness of the track bed.
It has become commonplace for railroad companies to periodically remove and clean the stone ballast from the shoulders of railroad track beds. Such periodic cleaning of the ballast from the track shoulders allows for adequate drainage of water from the track bed, even when the ballast from the center of the track bed is not removed and cleaned. The stone ballast is typically removed from the track bed shoulder, carried to a vibrating screen separator where the stone ballast is separated from dirt and debris, and the cleaned stone ballast is replaced along the track bed shoulder. The residual dirt and debris is deposited to one side or the other of the track bed, or can be collected in a separate car for removal from the cleaning site.
The process of cleaning railroad track shoulder ballast necessarily produces large amounts of airborne dust and debris. The generated dust and debris can seriously degrade the visibility in the immediate vicinity of the shoulder ballast cleaner, making it difficult or impossible for the operator to view and control the cleaning operation. Moreover, the resulting degradation in air opacity and overall air quality can reach unacceptable levels, and ballast cleaning operations have come under the scrutiny of several governmental agencies concerned with the maintenance of air quality standards. Since there has heretofore been no suitable apparatus for controlling the dust and debris generated in rail shoulder ballast cleaning operations, necessary railroad track maintenance has, on occasion, been delayed and even cancelled.
A dust suppression system for a railroad shoulder ballast cleaning machine that could suppress the airborne dust and debris generated by the shoulder ballast cleaning operation, would fill a long felt need in the railroad maintenance industry.